On Wed, Jun 11, 2025 at 03:21:38PM -0400, Stefan Hajnoczi wrote:
> On Wed, Jun 11, 2025 at 2:03 PM Daniel P. Berrangé <berra...@redhat.com> 
> wrote:
> >
> > FYI, this seabios 1.17.0 release appears to have broken the
> > ability to use virtio-pci with libguestfs+QEMU:
> >
> >   https://bugzilla.redhat.com/show_bug.cgi?id=2372329
> >
> > so I'd suggest we hold off on this pull request until
> > the regression is diagnosed.
> 
> Thanks, Daniel. I have pushed a revert to staging.

This has been diagnosed now.

Old SeaBIOS would unconditionally add ACPI tables, even when QEMU
machine type had acpi=off. libguestfs forgot to ask for ACPI in
its libvirt XML, so was getting acpi=off as far as QEMU was
concerned, but SeaBIOS was none the less creating ACPI tables.

It was a miracle this worked because the ACPI tables were
designed for i440fx, but somehow Linux still booted with
them under q35.

So, the SeaBIOS update has a functional change, but that
was intentional & desirable, and the root bug was the lack
of request for ACPI in libguestfs.

So no need to revert anything

With regards,
Daniel
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